China Mobile and Softbank Japan are deploying thousands. The three major Indians, Sprint & Verizon in the U.S., and True in Thailand are serving customers. I expect the Deutsche Telekom and Vodafone soon and dozens more in the next few years. The performance varies strongly with the terrain. Softbank reports results as high as a 10X improvement but the 3X reported by Huang Yuhong of China Mobile is more typical.
It works and is deployed in dozens of places, including British Telecom and AT&T. T reports typical speeds of 750 megabits, up and down combined. The highest speeds go less than 150 meters, which is fine for fiber to the basement. In 2018, 212 MHz chips will double that speed. Plans include 10M homes passed by BT and a million at nbn Australia.
Verizon & Korea are building. NTT DOCOMO & China Mobile close. Many others mostly holding back, doing little until 2021-2023.
2019 for mobile phones, Qualcomm promises, as TSMC ramps 7 nm process to produce the chips.
Latency will be 5-10 milliseconds to the cloud controller intelligence.